232 THE DOMESTIC SHEEP. 



having the property of giving a softness and elasticity to 

 the fiber which is one of the distinguishing features of 

 wool. Over this central core is the second layer called the 

 corticle substance. This is the fibrous part of the fiber, to 

 which its strength is due. It contains the coloring matter. 

 It is really a fibrous thread and is striped lengthwise. This 

 fiber grows from the root which is seated in the nutritive 

 follicle in the lower skin. It has such a formation as gives 

 to it the waved and spiral character, and causes it .to twist 

 easily and become matted together under certain processes 

 known as felting. It also enables it to sustain and preserve 

 the twist which is given to it in the process of spinning. 

 But the most remarkable and special feature of wool is its 

 outer covering. 



This outer covering consists of pointed scales, the ex- 

 tremities of which are sharp. These are arranged around 

 the fiber in spirals. 



PIG. 3. FIG. 4. FIG. 5. 



Fig. 2, Fiber of Merino wool. 



Fig. 3, Cross section through a fiber of Merino wool. 

 Fig. 4, Single fiber of Merino wool. Fig. 5, Lock of Merino wool. 



Fig. 2. The sharp points are more distinctly shown at 

 fig. 3, which represents a fiber of wool cut down the 

 center. But all kinds of wool are not precisely alike in this 

 respect. Fine wools as that of any one of the Merinos, are 

 more liberally furnished with these serrations than other 

 kinds. In the finest Saxony wool these number as many 

 as 2,800 to the single inch. Wool of the finest Southdown 

 has about 2,000; and of the Leicester about 1,800. The fins 

 wool, too, has a much more wavy disposition, as is shown at 

 figures 4 and 5. This selection of illustrations has been 

 made for the purpose of explaining the peculiar property 



